Thermostatically controlled flatiron



Oct. 22, 1957 F. E. FINLAYSON 2,810,813

THERMOSTATICALLY CONTROLLED FLATIRON Filed Oct. 27, 1954 2 Sheets-Sheet1 in Van c 02": Frank 5 F/n/ gsan,

United States Patent 2,810,813 THERMOSTATICALLY CGNTROLLED FLATIRONFrank E. Finlayson, Ontario, Calif., assignor to General ElectricCompany, a corporation of New York Application October 27, 1954, SerialNo. 464,978 2 Claims. (Cl. 21925) My invention relates to electricflatirons, more particularly to such flatirons including a thermostaticmechanism for controlling the temperature thereof.

Since different materials require different temperatures for optimumironing thereof, electric fiatirons are conventionally provided withadjustable thermostatically controlled mechanisms for maintaining thetemperature of the iron at any desired temperature over a substantialrange. This is usually a somewhat complex mechanism requiring a numberof parts and a substantial frame for carrying the various parts. Inaccordance with my invention, the construction has been simplified bymounting the parts in such a manner as to eliminate the need for theframe and by combining functions so as to reduce the number of partsrequired. More specifically I have provided an improved arrangement inwhich the parts may be mounted on the cover or shell of the iron so thatthe cover itself acts as a frame. Alternatively some of the parts may bemounted on the handle so that a combined assembly of a handle and thecover acts as the frame for the thermostatic mechanism. Moreover, I haveprovided an improved arrangement which facilitates manipulation of thecontrol by the thumb or finger of the user.

t is an object of my invention to provide an improvedthermostatically-controlled electric flatiron which is simple inconstruction and employs a minimum of parts.

It is another object of my invention to provide an improvedthermostatically-controlled electric fiatiron in which a major componentof the iron itself, for example, the cover, also provides a frame forthe thermostatic mechanism. It is a further object of my invention toprovide an improved arrangement utilizing a hollow front handle supportfor facilitating convenient adjustment of the thermostatic mechanism.

Further objects and advantages of my invention will become apparent asthe following description proceeds. The features of novelty whichcharacterize my invention are pointed out with particularity in theclaims annexed to and forming part of this specification.

in carrying out the object of my invention in one form thereof, a switchmechanism is mounted on one portion of the cover and the adjustingmeans, comprising a combined cam and cam-actuating member, is mounted onanother portion of the cover in such a manner as to cooperateeifectively with the switch mechanism. A temperature-responsive elementis mounted on the soleplate and arranged to engage the mechanism foropening and closing the contacts. Alternatively, the switch mechanismmay be mounted on the cover and the adjusting means mounted inappropriate relationship on the handle. In either case an easilyaccessible calibrating member is provided for making a satisfactoryfactory adjustment of the temperature setting. The adjusting means isarranged for convenient finger manipulation by the user.

For a better understanding of my invention reference may be had to theaccompanying drawing in which:

Fig. 1 is an elevation view, partly in section, of an 2,810,813 PatentedOct. 22, 1957 2 electric flatiron incorporating an embodiment of myinvention.

Fig. 2 is a bottom plan view of the fiatiron shown in Fig. 1, thesoleplate being removed.

Fig. 3 is an elevation view, partly in section, fied form of myinvention.

Fig. 4 is a bottom view, of the iron shown in Fig. 3.

Fig. 5 is a partial sectional elevation illustrating a modified form inwhich this invention may be carried out.

Referring to Figs. 1 and 2, there is shown an electric fiatiron whichincludes a soleplate 1, a cover or shell 2, and a handle 3. The handleis formed of a conventional, electrically-insulating material. Heat issupplied to the soleplate by a heating element 4, preferably of thesheathed type, embedded in the soleplate 1. Conventionally, the heatingelement 4 is generally U-shaped and includes two terminals at the rearend, one of which is shown at 5.

In the form illustrated the cover 2 is secured to the soleplate by twoscrews (not shown) which are received in openings 6 in the cover. Eachof the screws is received in a corresponding threaded boss 7 extendingupwardly from the soleplate 1 and formed integral therewith. The rearportion of the handle is held in assembled relation with the cover byscrews 8 which pass through openings in the cover and are received inthreaded recesses (not shown) in the bottom of the handle 3. The forwardportion of the cover and the corresponding portion of the handle areheld in assembled relation by means of a bracket 9. One end of thebracket 9 is mounted on the handle by the means of a screw 9a receivedin a threaded recess in the handle. The other end of the bracket 9 issecured by a screw or other suitable fastening device 9b to the cover 2.

In order to control the temperature of the iron so as to maintain itwithin any desired range, a thermostatic switch mechanism, indicatedgenerally at 10, is employed. The switch structure is supported from thecover 2 by an insulating member or block 11 mounted on the underside ofthe cover 2. Block 11 may be formed of any suitableelectrically-insulating material. The block 11 may be secured to thecover 2 in any suitable manner, for example, by means of rivets 12passing through openings in the block and in the cover 2. A leaf spring13, which is in the form of a long flexible resilient member, is mountedat its rear end on the insulating block 11 by means of suitablefastening devices, such as the rivets 14. A fixed contact 15 is mountedon an arm 16 which is secured in any suitable manner, as by rivets 17,to the insulating block 11. A movable contact 18 is provided forcooperation with the fixed contact 15 to make and break circuit to theheating element 4. This movable contact 13 is mounted on an arm 19 whichextends rearwardly from the free or forward end of the leaf spring 13.

In the specific form illustrated the free or forward end of the leafspring 13 is secured to the switch arm 19 in any suitable manner, as byriveting or welding. An insulator 2% is then secured to the extremeforward end of the switch arm 19. It will be apparent, however, that theleaf spring 13, the switch arm 19 and the insulator 20 may be connectedtogether in a number of different ways. For example, the forward ends ofboth the leaf spring 13 and the switch arm 19 may be received by a pressfit in a recess in the insulator 20, the insulator then being mounted onthe ends of both of these members 13 and 19. Also, if desired, themembers 13 and 19 can be formed from a single strip of material foldedback upon itself at the forward end. However, it is usually moredesirable to have the switch arm 19 of a more rigid material than therelatively resilient leaf spring 13 and accordingly it is preferablethat the two members 13 and of a modiwith the soleplate removed,

' 3 19 be formed of separate strips connected in a suitable manner nearthe forward ends thereof.

Since it does not form part of my invention, the details of the ironcord and its connection to the iron have not been shown. It will beapparent from the illustration, however, that the arm 16 from the fixedcontact 15 includes a rearward extension 21 to which one end of theelectric supplycord is connected. The other end of the supply cord, thatis the other side of the power supply, is connected to a strip 22 whichin'turn is connected by a strap 23 to one end or terminal of the heatingelement 4. The other end of the heating element is connected by acorresponding strap to a rearward extension 24 of the leaf spring 13.Thus, the switch mechanism is connected in series with the heatingelement so as to control the supply of electrical power to the heatingelement.

In order to control the actuation of the movable switch contact foropening and closing the thermostatic switch mechanism 10, atemperature-responsive element 25 is provided. In the form illustrated,the temperatureresponsive element 25 is in the form of a two-partbimetallic strip. The two sitioned bimetals in accordance with theinvention of Russell A. Windborne, described and claimed in Patent2,128,869, and assigned to the assignee of the present invention. Thebimetallic strip 25 is mounted in heat exchange relationship with thesoleplate 1. Specifically, in the form illustrated, one end of thebimetallic strip 25 is mounted in direct contact with a boss 26 formedintegral with the soleplate 1. The bimetallic strip 25 is held inintimate contact with the boss 26 by a screw 27 received in a threadedrecess in the boss 26.

An actuating arm or member 28 is connected to the free end of thebimetallic strip 25 and extends upwardly therefrom to effect actuationof the switch arm 19 and hence of the movable contact 18. Actualengagement of the switch arm 19 is effected by means of a calibratingscrew 29. The calibrating screw is threadedly received in an opening ina flange 30 at the top of the actuating member 28. The screw includes aprojection or tip 31 of electrically insulating material which engagesthe switch arm 19. The bimetallic strip 25 is arranged so as to benddownwardly as the temperature increases. It can be seen, therefore, thatas the temperature of the soleplate increases to a predeterminedmaximum, downward movement of the bimetallic strip 25 and hence of thecalibrating screw 29 ultimately causes the switch arm 19 to be moveddownward to an extent sufficient to break the circuit of the heatingelement at the contacts 15, 18.

In order to adjust the temperature setting of the thermostatic switchmechanism, a cam 32 is provided for engagement with the insulator or camfollower 29. In accordance with my invention, this cam 32 is alsomounted on the cover 2. Specifically the cam 32 is rotatably receivedwithin an opening in the cover 2. A suitable fastening device, forexample, a rivet 33 is employed together with a spring washer 34 forholding the cam 32 in the desired rotative relationship with the cover2. To facilitate rotational movement of the cam, a plurality ofprojections 33a may be formed extending downwardly from the cover 2. Inorder to provide for adjusting the position of the cam 32, a controllever or cam-actuating member 35 is provided. In the form illustratedthis lever is formed integrally with the cam 32 and thus the functionsof the control lever and the cam are combined in one part. The controllever 35 isarranged to extend upwardly through an arcuate slot 36 inthecover 2 and through a gap 37 between a saddle plate 38 and the handle 3.A control knob 39 is provided on the extremity of the control lever 35for facilitating actuation thereof.

It will be apparent that there may be some variations in therelationship of the various parts of the assembled structure as a resultof variations during the manufacturing operation. In order to provide anaccurate setting parts consist of reversely poof the temperature of theiron despite such variations, the calibrating screw 29 is provided.Access to the calibrating screw after assembly of the iron has beencompleted is provided by an opening 40 in the cover 2 in alignment withthe calibrating screw 29. Thus, before the saddle plate 38 is assembled,the calibrating screw may be readily adjusted by a tool inserted in theopening 4% so that the temperature of the iron coincides with thetemperature indicated on a dial adjacent to the control lever 35. Afterthe iron has been properly calibrated by adjusting the screw 29, thesaddle plate 40 is assembled on the iron.

The cam 32 is shaped, as illustrated, to provide a surface of varyingheight in engagement with the insulator 20. The insulator 20 ismaintained continuously in engagement with the surface of the cam 32because of the natural resilience of the leaf spring 13. In order toadjust the temperature setting of the iron, the control knob 39 and thecontrol lever 35 are moved in a horizontal plane to rotate the cam 32.In the position illustrated in Fig. l, the temperature is set at arelatively high value. if it is desired to lower the temperature, thecontrol lever 35 is moved to rotate the cam so that the insulator 20 isallowed to move upwardly, carrying with it the end of the switch arm 19In this new position of the switch arm 19, it will require a smallerdownward movement of the free end of the bimetallic strip 25, and of thecalibrating screw 29, to effect engagement with and movement of theswitch arm 19 for breaking the circuit at the contacts 15, 18.

It can be seenthat by the structure utilized in my invention, the cover2 acts as the frame for the thermostatic controlling mechanism, and theswitch structure and the adjustable control therefor are allconveniently mounted upon this existing part of the iron. In addition,the temperaturearesponsive element which is mounted on and is directlyresponsive to the temperature of the soleplate is easily related to andcoordinated with the thermostatic switch mechanism for actuating theswitch.

A modified form of my invention is shown in Figs. 3 and 4. Correspondingparts have been indicated by the same numerals in Figs. 1 and 2 andFigs. 3 and 4. The structure shown in Figs. 3 and 4- includes asoleplate 1, cover or shell 2 and a handle 3. The cover 2 is assembledon the soleplate 1 in the same manner as in the form previouslydescribed. The rear end of the cover 2 is connected to the handle byscrews 8, as in the form previously described. The forward portion ofthe handle and the cover are connected together by a screw 41, whichextends through an opening in the cover and is received in a-threadedopening in the handle 3. The iron includes a thermostatic switchmechanism indicated generally at 42. The modified form of my inventiondiffers from that previously described primarily in that the cam ispositioned at the upper end of a passage 43 in a hollow front supportingportion of the handle 3 in lieu of being mounted directly on thecover 2,and a connecting member extends vertically through the passage 43 tocooperate with the camand the switch mechanism.

Thus the structure includes a leaf spring 44 correspond ing to the leafspring 13 in the form illustrated in Fig. l. The leaf spring 44 issimilarly mounted on the insulating block 11. On the forward or-free endof the leaf spring 44 there is mounted an L-shaped member 45. The leafspringmay be connected to-the member 45 in a suitable manner, as bywelding or brazing. The switch arm 46 is shaped as illustrated andincludes a movable contact 18 mountedon the rear end thereof and adaptedto cooperate with the fixed contact 15. The switch structure includingthe leaf spring- 44' and the switch arm 46 has connected thereto attheforward end thereof, an upwardly extending, generally vertical elongatedmember 47 which is positioned in the passage 43 of the aforementionedhollow front supportingportion of the iron handle. A pin or otherfastening device 48 is provided for connecting the member 47 pivotallyto the forward end of the switch arm 46 and to the L-shaped member 45 onthe leaf spring 44. The upper end of the member 47 is slidably mountedin a recess 49 formed in the iron handle 3 adjacent to the uuper end ofthe passage 43.

In order to effect adjustment of the temperature setting of the iron, acontrol lever 50 is provided at the upper end of the passage 43. Thecontrol lever extends through a transverse passage or slot 51 in thefront of the handle, and includes a knob 52 on the forward end foractuation thereof. A suitable indicating dial 53 is provided adjacent tothe control knob 52 for indicating the temperature setting of the iron.The rear end of the control lever is formed to include a cam 54 at theunderside thereof. The combined control lever and cam is formed toprovide a circular raised portion 55 which cooperates with a circularrecess in the dial plate 56. The raised portion has an opening 57therein of sufficient diameter to clear the member 47.

In order to transmit motion from the cam surface to the thermostaticswitch mechanism, an insulator or cam follower 58, corresponding to theinsulator 20 of the form shown in Fig. 1, is mounted on a laterallyextending projection 59 formed integrally with the member 47. Thisinsulator 58 is urged into constant engagement with the surface of thecam 54 by the resilience of the leaf spring 44 which urges the member 47and its associated insulator 58 upwardly.

The adjustment of the temperature setting by the means of a controllever 50 is accomplished in the same general manner as in the formpreviously described. Thus, as the control lever is rotated in ahorizontal plane, the cam 54 affects the position of the insulator 58and hence the member 47. For example, as the control lever is rotatedfrom the position shown, the cam surface forces the insulator 58 and themember 47 downwardly. This moves the switch arm 46 downwardly, therebymaking a greater movement of the bimetallic strip 25 necessary in orderto engage the switch arm 46 and actuate the movable contact 18 forinterrupting the heating circuit. Accordingly, a higher temperature ofthe iron will be maintained.

In this modified form of my invention, it can be seen that the structureis simple and the number of parts required are again minimized, sincethe frame for the thermostatic mechanism is furnished by the combinationof the cover and the handle mounted thereon. Also the functions of thecontrol lever and the cam are directly combined in one member, thestructure being arranged so that an insulator on the switch mechanism isheld by the leaf spring 44 constantly in engagement with the cam surfaceof the combined cam and cam actuating member.

Another modified form of a portion of an iron embodying my invention isshown in Fig. 5. This form differs from those previously described onlyin that the insulating member which supports parts of the thermostaticmechanism is mounted on the soleplate 1. The same numerals have beenemployed to designate the same parts in Fig. as in the forms previouslydescribed. The same numerals with a subscript a added have been employedto designate a modified part corresponding to the parts used in theforms previously described.

Referring to Fig. 5 an insulating member 11a, used for mounting parts ofthe thermostatic switch mechanism, is mounted on a boss 60 extendingupwardly from the soleplate 1 by means of screws 61 or other suitablefastening devices. Except for the fact that the insulating member 11a ismounted on the soleplate rather than on the cover, the remainder of themechanism employed is the same as that shown in the form illustrated inFigs. 1 and 2 or the form illustrated in Figs. 3 and 4.

While I have shown and described specific embodiments of my invention, 1do not desire my invention to be limited to particular constructionsshown and described, and I intend by the appended claims to cover allmodifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In an electric flatiron including a soleplate, a cover, and a handle,a thermostatic mechanism for controlling the temperature of saidflatiron, said mechanism including an insulating member mounted on saidcover, a leaf spring having one end mounted on said insulating member, amovable contact carried by said leaf spring, a stationary contactmounted on said insulating member and adapted to be engaged by saidmovable contact, a temperature-responsive element mounted on saidsoleplate for effecting movement of said movable contact into and out ofengagement with said fixed contact, said handle being formed to providea hollow supporting portion at the forward end thereof, a combined camand cam-actuating member positioned at the upper end of said hollowportion, an elongated member positioned in said hollow portion andadapted to be moved vertically by said cam for adjusting the temperaturesetting of said thermostatic mechanism, said handle including a recessat the upper end of said hollow portion, the upper end of said elongatedmember being slidably received in said recess, and an insulator mountedon said elongated member near the upper end thereof for engaging saidcam, the lower end of said member being mounted on the free end of said7 leaf spring whereby said leaf spring maintains said insulator inengagement with said cam.

2. In an electric flatiron including a soleplate, a cover, and a handle,a thermostatic mechanism for controlling the temperature of saidflatiron, said mechanism including an insulating member mounted on saidcover, a leaf spring having one end mounted on said insulating member, aswitch arm mounted on the free end of said leaf spring, a movablecontact carried by said arm, a fixed contact mounted on said insulatingmember and adapted to be engaged by said movable contact, atemperature-responsive element mounted on said soleplate for effectingmovement of said movable contact into and out of engagement with saidfixed contact, said handle being formed to provide a hollow supportingportion at the forward end thereof, a combined cam and cam-actuatingmember positioned at the upper end of said hollow portion, an elongatedmember positioned in said hollow portion, said handle' including arecess at the upper end of said hollow portion, the upper end of saidelongated member being slidably received in said recess, and aninsulator mounted on said elongated member near the upper end thereoffor engaging said cam, the lower end of said member being mounted on thefree end of said leaf spring whereby said leaf spring maintains saidinsulator in engagement with said cam.

References Cited in the file of this patent UNITED STATES PATENTS2,288,517 Dubilier June 30, 1942 2,408,886 Scarf Oct. 8, 1946 2,420,195Riker May 6, 1947 2,681,521 Finlayson et a1. June 22, 1954 FOREIGNPATENTS 461,461 Canada Nov. 29, 1949

